|
}} The DeTour Reef Light is a non-profit-operated lighthouse marking the southern entrance of the DeTour Passage between the eastern end of Michigan's Upper Peninsula and Drummond Island. The light is an automated active aid to navigation.〔(Michigan Lighthouse Conservancy, DeTour Reef Light. )〕 It marks the northern end of Lake Huron. The passage is used by almost all of the Great Lakes commercial freighter traffic moving to and from Lake Superior, with approximately 5,000 vessel movements annually. It is said to be "the gateway to Lake Superior."〔 In addition, many recreational boaters use the passage. The Light is located in Lake Huron, three miles (5 km) south of the nearest town, DeTour Village, Michigan. == Lighthouse history == The southern entrance to DeTour Passage is made dangerous by a shoal, DeTour Reef. In order to enter or leave the passage, boats must thread past a shallow area no more than deep. In 1847 a lighthouse was located on shore at Point DeTour, Michigan to protect the DeTour Passage at the northwestern end of Lake Huron. In 1931 it was moved offshore on to DeTour Reef. It is locally called the "Gateway to Superior”. The DeTour Reef Lighthouse, raised in 1931, not only marks the channel, but also is built atop DeTour Reef on a crib structure, and warns boats away from it. The lighthouse and its concrete base are tall.〔 After commercial bids were determined to be unsatisfactory, the light was constructed by the U.S. Army Corps of Engineers. The structure was finished in 327 working days.〔 This iteration of the light was built for $140,000. Some sources have described it as "Art Deco."〔(Interactive map on Michigan lighthouses, ) Detroit News.〕 The concrete foundation is similar to the Martin Reef Light located about to the west, and Poe Reef Light located near Cheboygan, Michigan. The same crew built all three lights around the same time.〔 It is almost a 'fraternal twin' of the Fourteen Foot Shoal Light which was built in 1930. In that sense, by using the same crews, equipment and personnel, the builders followed in the tradition of the builders of Spectacle Reef Light, White Shoal Light, and Waugoshance Light, thereby achieving real savings and efficiency. This light (and its predecessor) have gone through many different lenses in its 160-year history. *In 1848, the original illuminating apparatus was a fixed white light produced by 13 Argand lamps—the predecessor and original design of the so-called "Lewis lamp"〔(Lighthouse illumination, Terry Pepper, Seeing the Light. )〕—each with a reflector. It was designed with a 270-degree arc to conserve whale oil. *In 1857 a 4th order Fresnel lens producing a fixed white light was installed. *In 1870 a fixed, white, 3rd order Fresnel lens was installed. That year, the remnants of the original stone tower were removed. In 1907, the 3rd order lens was replaced by a 3½-order bi-valve lens. This lens did not last long. *In 1908 a rare 3½-order Order Fresnel lens, one of only a dozen used around the country, most of which were on the Great Lakes,〔( Terry Pepper, Seeing the Light ''3½-order Fresnel lens''. )〕 configured as a flashing white light with a characteristic of a one-second flash and a nine-second eclipse was installed. It had an effective range of . The lens was manufactured by Barbier, Benard & Turenne Co. of Paris, France. It has the number USLHE 317 stamped on it. These lights were typically reserved for places that were an especially serious hazard to navigation. ''See, for example,'' Sturgeon Point Light. Other Great Lakes lights that had 3½-order Fresnel lenses were at (in alphabetical order): Eagle Bluff, Grays Reef, Huron Island, Michigan Island, St. Helena Island, and Toledo Harbor.〔 *In 1931, a new Detour Reef light structure was introduced. The same lens was relocated to it, The light remained white. *In 1936, the color changed from straight white to white with a red sector that faced land. This was accomplished through the use of a color shade inside the lens room. *In 1978 this lens was dismantled. It is now on display at the DeTour Passage Historical Museum in DeTour Village, Michigan.〔(History of the DeTour light, DeTour Light Preservation Society. )〕 *The present optic is a Vega VRB-25 system〔(National Park Service, Maritime heritage, inventory of DeTour Reef Light. )〕 A concise explanation on the different lenses and their technology is available at (Lighthouse Illumination Technology, Terry Pepper, Seeing the Light. ) This is part of a larger pattern of building 14 reef lights around Michigan, which was intended to help ships navigate through and around the shoals and hazards.〔 (Roberts, Bruce; Jones, Ray. (September 2002) ''American Lighthouses, 2nd: A Definitive Guide'' pp. 246-250 Publisher: Globe Pequot Press 304 pp ) ISBN 978-0-7627-2269-3.〕 The station was equipped with a F-2-T diaphone fog signal, which was preserved at the Great Lakes Historical Society in Ohio. It has been returned to the custody of the lighthouse complex.〔(Terry Pepper, Seeing the Light, DeTour Reef Light. )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「DeTour Reef Light」の詳細全文を読む スポンサード リンク
|